Method for controlling operation of compressor and apparatus thereof

ABSTRACT

A method for controlling an operation of a compressor and its apparatus can easily control an operation of the compressor without a request for a high-priced operation control apparatus by operating the compressor with controlling the amount of currents flowing into a winding coil of a motor ( 100 ) of the compressor according to load capacity of the refrigerator. The apparatus includes a control unit ( 103 ) for generating a control signal for selecting a main winding coil (M) of a linear motor ( 100 ) of a compressor or an auxiliary winding coil (M 2 ) on the basis of the load capacity of a refrigerator, and a switching unit ( 101 ) for selecting the main winding coil (M) of the linear motor ( 100 ) or the auxiliary winding coil (M 2 ) on the basis of the control signal. Herein, the main winding coil of the linear motor ( 100 ) is divided into a plurality of auxiliary winding coils (M 2 ).

TECHNICAL FIELD

The present invention relates to a compressor and, particularly to amethod for controlling an operation of a compressor and an apparatusthereof.

BACKGROUND ART

Generally, in a compressor, particularly a reciprocating compressor,compression efficiency is higher than a general compressor since thereis no crankshaft for converting a rotational movement into a linearmovement, and thus a friction loss is small.

In case that the reciprocating compressor is used for a refrigerator oran air conditioner, as varying a stroke voltage applied to thereciprocating compressor (interior motor of the compressor), acompression ratio can be varied. For this reason, freezing capacity canbe controlled. The operation controlling apparatus for the reciprocatingcompressor will now be described with reference to FIG. 1.

FIG. 1 is a block diagram showing a structure of an apparatus forcontrolling an operation of a reciprocating compressor according to aconventional art.

As shown therein, the apparatus for controlling an operation of theconventional reciprocating compressor includes a voltage detecting unit14 for detecting a voltage applied to an interior motor 13 (illustratedas a coil of the interior motor) of the reciprocating compressor (notshown) when the reciprocating motor operates; a current detecting unit12 for detecting a current applied to the motor (M) 13 when thereciprocating compressor operates; a microcomputer 15 for calculating astroke of the compressor on the basis of a voltage value detected fromthe voltage detecting unit 14 and a current value detected from thecurrent detecting unit 12, comparing the calculated stroke and apredetermined stroke reference value, and outputting a switching controlsignal on the basis of the comparison result; and a power supply unit 11for supplying a stroke voltage to the motor 13 (M) by on-off controllingan interior triac (TR) according to the switching control signaloutputted from the microcomputer 15. Herein, a resistor (R) of the powersupply unit 11 is installed to detect a current applied to the motor 13(M).

Operations of the apparatus for controlling an operation of thereciprocating compressor according to the conventional art will now bedescribed.

First, the reciprocating motor receives a voltage supplied to the motor13 depending on the stroke reference value set by a user, varies thestroke and vertically moves an interior piston. Herein, the stroke meansa moving distance of the inner piston of the reciprocating compressorwhile the inner piston reciprocally moves.

A turn-on period of a triac of the power supply unit 11 is lengthened bya switching control signal outputted from the microcomputer 15. Analternating current power (stroke voltage) is supplied to the motor 13due to the lengthened turn-on period, and thus the motor 13 is driven.At this time, the voltage detecting unit 14 and the current detectingunit 12 detect the voltage and the current applied to the motor 13respectively, and output the detected voltage value and the currentvalue to the microcomputer 15.

The microcomputer 15 calculates a stroke of the compressor on the basisof the voltage value detected by the voltage detecting unit 14 and thecurrent value detected by the current detecting unit 12, then comparesthe stroke with the predetermined stroke reference value, and thenoutputs a switching control signal according to the comparing result.For example, when the calculated stroke is smaller than thepredetermined stroke reference value, the microcomputer 15 outputs aswitching control signal for lengthening a turn-on period of the triacto the power supply unit 11 and thus increases a stroke voltage suppliedto the motor 13. On the other hand, when the calculated stroke isgreater than the predetermined stroke reference value, the microcomputer15 outputs a switching control signal for shortening a turn-on period ofthe triac to the power supply unit 11 and thus decreases a strokevoltage supplied to the motor 13.

However, when the apparatus for controlling the operation of theconventional reciprocating compressor is installed at a refrigerator andcontrols on-off of a triac, a high-priced digital signal processor (notshown) for controlling the triac is used, and thereby increasing costsfor implementing the apparatus for controlling the operation of thereciprocating compressor.

DISCLOSURE OF THE INVENTION

Therefore, it is an object of the present invention to provide a methodand an apparatus for controlling an operation of a compressor capable ofeasily controlling an operation of a compressor without a request for ahigh-priced operation control apparatus by driving the compressor withcontrolling the amount of currents flowing into a winding coil of amotor of the compressor according to load capacity of a refrigerator.

It is another object of the present invention to provide a method and anapparatus for controlling an operation of a compressor capable of easilycontrolling an operation of a compressor without a request for ahigh-priced operation control apparatus by selecting a main winding coilor an auxiliary winding coil on the basis of a voltage applied to amotor of the compressor.

To achieve the above object, there is provided an apparatus forcontrolling an operation of a compressor including a control unit forgenerating a control signal for selecting a main winding coil of alinear motor of a compressor or an auxiliary winding coil on the basisof load capacity of a refrigerator; and a switching unit for selectingthe main coil of the linear motor or the auxiliary winding coil on thebasis of the control signal, wherein the main winding coil of the linearmotor is divided into a plurality of auxiliary winding coils.

To achieve the above object, there is also provided a method forcontrolling an operation of a compressor including the step of applyingpower to the main winding coil of the linear motor of the compressorinstalled at the refrigerator or the auxiliary winding coil of thelinear motor on the basis of an inside temperature of the refrigeratorand a predetermined reference temperature value, wherein the mainwinding coil of the linear motor is divided into a plurality ofauxiliary winding coils.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a structure for an apparatus forcontrolling an operation of a reciprocating compressor according to theconventional art;

FIG. 2 is a block diagram of a structure for an apparatus forcontrolling an operation of a reciprocating compressor according to anembodiment of the present invention; and

FIG. 3 is a flow chart showing an operation of an apparatus forcontrolling an operation of a reciprocating compressor installed at arefrigerator according to the present invention.

MODES FOR CARRYING OUT THE PREFERRED EMBODIMENTS

Hereinafter, with reference to FIGS. 2 and 3, will be described indetail, a preferred embodiment of a method for controlling an operationof a compressor and its apparatus in which there is no need for a Tr, ahigh-priced digital signal processor for controlling the Tr and acurrent detecting unit, capable of easily implementing the apparatus forcontrolling an operation of the reciprocating compressor at a low priceby driving the compressor with controlling the amount of currentsflowing into a winding coil of an interior motor (linear motor) of thereciprocating compressor according to load capacity of a refrigerator ora voltage applied to the motor. Herein, the load capacity may be aninside temperature of the refrigerator and an ambient temperature, etc.In addition, the load capacity may be changed according to an apparatus(e.g. air conditioner) where the compressor according to the presentinvention is installed.

FIG. 2 is a block diagram of a structure for an apparatus forcontrolling an operation of a reciprocating compressor installed at arefrigerator according to an embodiment of the present invention. Theapparatus for controlling the operation of the reciprocating compressoraccording to the present invention can be installed not only at arefrigerator but also at any apparatus (e.g. air conditioner) where thelinear motor is used.

As shown therein, the apparatus for controlling the operation of thereciprocating compressor includes a communication unit 104 for receivingtemperature information in the refrigerator from a microcomputer (notshown) installed at the refrigerator and controlling the refrigerator; acontrol unit 103 for generating a control signal for operating a motorin a full mode when power is applied to the refrigerator, determiningload capacity of the refrigerator on the basis of the temperatureinformation in the refrigerator, which is inputted through thecommunication unit 104, and generating a control signal on the basis ofthe determining result or on the basis of a voltage applied to theinterior motor of the compressor; a driving unit 102 for outputting adriving signal for varying capacity of the motor 100 of the compressoraccording to the control signal of the control unit 103; and a switchingunit 101 for selecting a main winding coil (M) of the motor or anauxiliary winding coil (M2) by being switched by the driving signal ofthe driving unit 102. Herein, the motor 100 of the compressor includesthe main winding coil (M), and the main winding coil (M) is divided intoa first auxiliary winding coil (M1) and a second auxiliary winding coil(M2). Preferably, a winding ratio of the first auxiliary winding coil(M1) of the motor to the second auxiliary winding coil (M2) isconfigured to be one of 2:1, 3:1, 4:1 and 5:1. Also, preferably, a relayis used for the switching unit.

Hereinafter, operations of the apparatus for controlling an operation ofthe reciprocating compressor according to an embodiment of the presentinvention will now be described in detail with reference to FIG. 3.

FIG. 3 is a flow chart showing operations of an apparatus forcontrolling an operation of a reciprocating compressor installed at arefrigerator according to the present invention.

First, when alternating current (AC) power is initially applied to therefrigerator (S11), the control unit 103 applies a control signal foroperating the interior motor 100 of the compressor in a power mode tothe driving unit 102. Herein, the power mode means a mode for operatingthe compressor at a maximum stroke when the AC power is initiallyapplied to the interior motor of the compressor of the refrigerator.That is, the power mode increases currents applied to the motor byreducing the winding number of the winding coil of the interior motor ofthe compressor.

The driving unit 102 switches the switching unit 101 so as to select theauxiliary winding coil (M2) of the motor 100 on the basis of the controlsignal. At this time, since the switching unit 101 is switched to theauxiliary winding coil (M2) by the driving unit 102, a current isapplied to the auxiliary winding coil (M2) of the motor 100, and thusthe reciprocating compressor operates at a maximum stroke. That is, ifthe current is applied through the auxiliary winding coil (M2), power ofthe linear motor is increased so that a maximum stroke volume (maximumcompression volume) can be obtained in a short time (S12). Herein, powerof the linear motor is increased since the amount of the currentsapplied through the auxiliary winding coil (M2) is greater than thatthrough the main winding coil (M).

Thereafter, while the control unit operates the motor 100 in a powermode, when a certain time (e.g. 10˜15 minutes) elapses (S13), thecontrol unit 103 applies a control signal for operating the compressorof the refrigerator in a full mode to the driving unit 102. Herein, thefull mode means a mode applying a current through the main winding coil(M) of the interior motor of the compressor when a certain time (e.g.5˜10 minutes) elapses during an operation of the motor 100 in the powermode. Since the full mode is a conventional art, a detailed descriptionthereof is omitted.

The driving unit 102 switches the switching unit 101 so as to select themain winding coil (M) of the motor 100 on the basis of the controlsignal. At this time, since the switching unit 101 is switched to themain winding coil (M) by the driving unit 102, power is applied throughthe main winding coil (M) of the motor (S14).

Thereafter, the control unit 103 receives temperature information on aninside temperature of the refrigerator and an ambient temperaturethrough the communication unit 104 from a microcomputer (not shown)installed at the refrigerator, and detects load capacity of therefrigerator on the basis of the received temperature information. Forexample, the control unit 103 calculates an average value of the insidetemperature of the refrigerator and the ambient temperature, anddetermines that the load capacity of the refrigerator is overloaded whenthe calculated average value is greater than a predetermined referencetemperature value.

On the other hand, when the average value of the inside temperature ofthe refrigerator and the ambient temperature is the same as or smallerthan the predetermined reference temperature value, the control unitdetermines that load capacity of the refrigerator is normal. Herein, thecontrol unit 103 may determine whether load capacity of the refrigeratoris overloaded or normal on the basis of at least one of the insidetemperature of the refrigerator and the ambient temperature. Also, thecontrol unit 103 may determine whether the load capacity of therefrigerator is overloaded or normal on the basis of the average valueof the inside temperature of the refrigerator and the ambienttemperature (S15),

The control unit operates the interior motor 100 of the compressor in afull mode or in a power mode on the basis of the load capacity of therefrigerator. That is, when the average value of the temperatures isgreater than the predetermined reference temperature value, in otherwords, when the load capacity of the refrigerator is overloaded (S16),the control unit 103 operates the compressor in the power mode, and thuslowers a temperature in the refrigerator rapidly (S17). For example, inoperating the compressor in a full mode, if the inside temperature ofthe refrigerator is greater than the predetermined reference temperaturevalue (when the refrigerator is overloaded), a piston of the compressoris pushed whereby the maximum stroke volume (maximum compression volume)can not be obtained, and thus the inside temperature of the refrigeratoris not decreased. Accordingly a current is applied through the auxiliarywinding coil (M2) so that power of the linear motor can be increased,and thus the maximum stroke volume (maximum compression volume) can beobtained in a short time.

On the other hand, when the average value of the temperatures is thesame as or smaller than the predetermined reference temperature value,that is, when the load capacity of the refrigerator is normal, thecontrol unit 103 operates the compressor in the full mode (S18).

When a voltage applied to the motor decreases, the control unit outputsa control signal for operating the motor in the power mode. When avoltage applied to the motor increases or stays in the same amount, thecontrol unit outputs a control signal for operating the motor in thefull mode. That is, since a stroke of the compressor is decreased when avoltage applied to the motor decreases, the control unit outputs acontrol signal for operating the linear motor in the power mode in orderto prevent the decrease of the stroke of the compressor.

Accordingly, in the present invention, an apparatus for controlling anoperation of a compressor can be easily implemented at a low price byreliably controlling a reciprocating compressor installed at arefrigerator without a high-priced apparatus for controlling theoperation of the compressor.

As so far described, since a method and an apparatus for controlling anoperation of a compressor according to the present invention operatesthe compressor with varying the winding number of the interior motor towhich a current is applied, on the basis of load capacity of therefrigerator or a voltage applied to the interior motor of thecompressor, there is no need for a high-priced operation controlapparatus, and an apparatus for controlling an operation of thecompressor can be implemented at a low price.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention cover modifications and variationsof this invention provided they come within the scope of the appendedclaims and their equivalents.

1. An apparatus for controlling an operation of a compressor comprising:a control unit for generating a control signal for selecting a mainwinding coil of a linear motor of a compressor when at least one of aninside temperature of a refrigerator and an ambient temperature is thesame as or smaller than a predetermined reference temperature value oran auxiliary winding coil when at least one of the inside temperature ofthe refrigerator and the ambient temperature is greater than thepredetermined reference temperature value; and a switching unit forselecting the main winding coil of the linear motor or the auxiliarywinding coil on the basis of the control signal, wherein the mainwinding coil of the linear motor is divided into a plurality ofauxiliary winding coils, load capacity is determined based on at leastone of the inside temperature of the refrigerator and the ambienttemperature, and the control unit controls the amount of currentsflowing into the winding coil of the linear motor by computing thegenerated control signal.
 2. The apparatus of claim 1, wherein thecontrol unit generates the control signal for selecting the winding coilof the linear motor or the auxiliary winding coil when a voltage appliedto the linear motor is varied.
 3. The apparatus of claim 1, wherein thecontrol unit generates the control signal for selecting the main windingcoil of the linear motor or the auxiliary winding coil in order tocontrol the amount of currents flowing into the winding coil of thelinear motor.
 4. The apparatus of claim 1, wherein the switching unit isa relay.
 5. A method for controlling an operation of a compressorcomprising: applying power to a main winding coil of a linear motor of acompressor installed at a refrigerator when an inside temperature of therefrigerator is the same as or smaller than the predetermined referencetemperature value or to an auxiliary winding coil of the linear motorwhen the inside temperature of the refrigerator is greater than thepredetermined reference temperature value, wherein the main winding coilof the linear motor is divided into a plurality of auxiliary windingcoils.